Very useful forms of axial piston rotary engines were described and illustrated in U.S. Pat. No. 5,813,372, as apparent especially from the assembly drawing of FIG. 11 thereof, and it is to be understood that all the disclosures of that specification are to be deemed part of the disclosure herein to the extent that the same may be pertinent and/or desirable. In such engines a plurality of pistons are mounted in cylinders as part of a rotor assembly, the pistons cooperating with a cam track to cause rotation of the rotor assembly upon combustion of fuel in the cylinder in a manner typical of piston type internal combustion engines. In this specification, the terms "top end" and "bottom end" are used to refer to the combustion end and drive end of the engine as will be understood by those familiar with piston type internal combustion engines.
It is an object of the invention to provide an axial piston rotary engine of the general type described in the said PCT application in which the thrust on the inlet and/or exhaust port seals is reduced.
It is another object of the invention to provide an axial piston rotary engine of the general type described in the said PCT application in which the bottom end of the engine is sealed from the top end so that lubricant required for the cam track, cam follower, cylinder walls and other bottom end components is prevented or at least substantially prevented from entering the combustion chamber via the inlet ports.
It has been known for a considerable period that timing of opening and closing of inlet and exhaust ports has a significant effect on the operation of internal combustion engines and that the efficiency of internal combustion engines can be increased by varying the timing particularly the timing of opening of the inlet ports in operation. It is thus an object of the present invention to provide an axial piston rotary engine of the general type described in the said PCT application which lends itself to variable inlet timing.
It is another object of the invention to provide an axial piston rotary engine which lends itself to variable length piston stroke for varying the compression ratio whereby different fuels can be used effectively.